1. Field of the Invention
The present invention relates to a shot processing apparatus, and more particularly to shot processing apparatus for shot processing a workpiece by projecting projection material.
2. Description of the Related Art
A drum type shot processing apparatus is known whereby processed parts are placed into a drum and subjected to shot processing while being stirred inside the drum (Patent Document 1).
This drum-type shot processing apparatus comprises a cylindrical drum with a bottom, open at one end, and a centrifugal projector disposed at the opening end of the drum. The projector has a cylindrical control cage with an opening window formed in its outer perimeter wall, from which projection material supplied to the inside is discharged, and blades which rotate outside of this control cage.
When performing shot processing, multiple workpieces are loaded into the drum. As the drum is then rotated about its center axis and workpieces inside the drum are stirred on the bottom portion of the drum, projection material is projected from a projector onto the workpieces in the drum, polishing (cleaning) or otherwise treating the workpieces.